1. Technical Field
The present invention relates to an outrigger connection locking device that is used in a crane apparatus having outriggers removably mounted to a carrier frame that supports a boom, for locking the connection between the carrier frame and the outriggers.
2. Related Art
In recent years, large crane apparatuses, which are not legally permitted to run on public roads, have been developed. Such a large crane apparatus has to be divided into several parts and delivered by a deliver vehicle, and then, the divided parts are assembled on a work place.
Here, among parts of the crane apparatus, an outrigger is particularly heavy, and therefore is supposed to be taken on a trailer and delivered separately from a carrier frame (crane apparatus body), and then, is connected to the carrier frame on the work place. In this case, the outrigger may not be welded to but connected to the carrier frame with pins, and therefore can be removably connected to the carrier frame as disclosed, for example, in Patent literature 1. Meanwhile, when there is not enough space for the worker to connect the outrigger to the carrier frame with pins, each pin may be attached to, for example, the tip of a hydraulic cylinder and the hydraulic cylinder is extended by remote operation, so that the pins can be inserted into pin holes.
Patent Literature 1: Japanese Patent Application Publication No. 2000-143157
However, when the hydraulic cylinder is extended to insert a pin into a pin hole, the pin sometimes drops off when the hydraulic cylinder contracts due to a decrease in the hydraulic pressure. Therefore, it is preferable to automatically keep the hydraulic cylinder extended. Here, a working space is required to automatically lock the connecting pins inserted into the pin holes by extending the hydraulic cylinder. However, there is not always the working space for the connection between the carrier frame and the outrigger.